Ok I have just found my pregnancy notes, I guess they might be the same as yours, op.
The section on bfeeding is as follows.
"Breastmilk contains antibodies which help protect you baby from infections such as,
Gastro enteritis
Chest and Ear infections
Urinary tract infections
It also reduces the risk of
Eczema
Allergies where there is a family history
Diabetes
And possibly Bowel diseases later in life
Breastfeeding will also....
Reduce your (the mother's) risk of premenopausal breast and ovarian cancer."
There is absolutely nothing about babies suffering more childhood cancers.
Also isn't it the case that something between 70 and 80% of women start off breastfeeding, but stop early. So your argument that "near on 80% artificially feeding at 6months indicates that it's a choice ", is surely not so much because those women are ignorant of the health risks associated with formula, and so choose to f'feed because they believe it is just as good as b'feeding, and more to do with the lack of support when establishing b'feeding, and misinformation about the realities of b'feeding (eg supply issues etc).